gl_utils: Make it harder to use uinitialized texture

src/video_display/opengl_utils.cpp

@@ -367,6 +367,11 @@ void Texture::init(){
         glGenBuffers(1, &pbo);
 }
 
+void Texture::bind() {
+        init();
+        glBindTexture(GL_TEXTURE_2D, tex_id);
+}
+
 
 void Framebuffer::attach_texture(GLuint tex){
         glBindTexture(GL_TEXTURE_2D, tex);
@@ -383,7 +388,7 @@ void Framebuffer::attach_texture(GLuint tex){
 
 void FrameUploader::put_frame(video_frame *f, bool pbo_frame){
         assert(tex);
-        glBindTexture(GL_TEXTURE_2D, tex->get());
+        tex->bind();
         tex->allocate(f->tiles[0].width, f->tiles[0].height, GL_RGB);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

src/video_display/opengl_utils.hpp

@@ -57,6 +57,7 @@
 //#include <SDL2/SDL_opengl.h>
 #include <mutex>
 #include <memory>
+#include <cassert>
 
 #include "types.h"
 
@@ -149,9 +150,9 @@ public:
         ~Texture();
 
         /**
-         * Returns the underlying OpenGL texture id
+         * Returns the underlying OpenGL texture id.
          */
-        GLuint get() const { return tex_id; }
+        GLuint get() const { assert(tex_id); return tex_id; }
 
         /**
          * Allocates the the storage for the texture according to requested
@@ -163,6 +164,13 @@ public:
          */
         void allocate(int w, int h, GLint internal_fmt);
 
+        /**
+         * Creates the actual OpenGL texture objects if not yet created
+         */
+        void init();
+
+        void bind();
+
         /**
          * Uploads video frame to the texture
          *
@@ -189,7 +197,6 @@ public:
                 std::swap(pbo, o.pbo);
         }
 private:
-        void init();
 
         /**
          * Uploads image data to the texture